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Bacillus megaterium
Back to Bacteria Information Overview Bacillus megaterium is a gram positive, endospore forming, rod shaped bacteria. It is considered aerobic. It is found in soil and considered a saprophyte. Bacillus megaterium is Latin for the big beast because it is an extremely large bacteria, it is about 100 times as large as E. coli. Due to its immense size, about 60 micrometers cubed, B. megaterium has been used to study structure, protein localization and membranes of bacteria since the 1950’s. Most notably, B. megaterium'' is the organism that was used by Lwoff and Guttman in the'' studies that discovered lysogeny. Cell structure and metabolism Gram positive rod, that is motile. It is not capable of butanediol fermentation. B. megaterium has been an important industrial organism for decades. It produces penicillin amidase used to make synthetic penicillin, various amylases used in the baking industry and glucose dehydrogenase used in glucose blood tests. Further, it is used for the production of pyruvate, vitamin B12, drugs with fungicidal and antiviral properties, etc.2 It produces enzymes for modifying corticosteroids, as well as several amino acid dehydrogenases. B. megaterium is known to produce poly-γ-glutamic acid. The accumulation of the polymer is greatly increased in a saline (2–10% NaCl) environment, in which the polymer comprises largely of L-glutamate (L-isomer content up to 95%).4 At least one strain of B. megaterium can be considered a halophile, as growth on up to 15% NaCl has been observed. Ecology Habitat; symbiosis; contributions to the environment. megaterium grows at temperatures from 3 °C to 45 °C, with the optimum around 30 °C. Some isolates from an Antarctic geothermal lake were found to grow at temperatures up to 63 °C. B. megaterium has been recognized as an endophyte and is a potential agent for the biocontrol of plant diseases. Nitrogen fixation has been demonstrated in some strains of B. megaterium. Pathology Considered non-pathogenic Genome structure Bacillus megaterium is one of the first bacteria's genome that has been fully coded. Current Research B. megaterium has often been used in the laboratory, and is used as an industrial organism that is able to produce a variety of proteins and sources of bioremediation. Bacillus megaterium is a good source of industrial proteins because it is both a desirable cloning host and produces a large variation of enzymes. This species is good cloning host because it is able to house numerous plasmid vectors while remaining stable due to its unique external proteases. The organism does not have alkaline proteases; which allows for recombinant protein synthesis. Using Bacillus megaterium'' scientist have developed numerous proteins that are'' commonly used in the medical and agricultural field. For example, many synthetic penicllins have been derived using the penicillin amidase in the bacteria; harvested glucose dehydrogenase is used in glucose blood tests; ß-Amylases which are often used in the bread industry; and neutral proteases which are used by the leather industry. Several strains have proven to be good hosts for gene expression. One strain, QM B1551, is still used to produce the antigen for HIV Diagnostic Kits. The biotechnological study of the Bacillus megaterium'' provides a plethora of different proteins that they are'' able to employ in important medical, scientific and industrial advances.